want to know who out there has had any real world improvement (not driveability) from changing plugs and gap on a before and after run on a dyno with a vehicle over 375RWHP. What has anyone seen and what were the mods. I understand the rule of thumb about Gap and a step colder for any serious HP over stock...yadda yadda yadda. For example a 400RWHP car with TR6's gapped @ .035 as opposed to .050? Anyone?

 

there isn't going to be any HUGE power gains or anything, it's just that factory plugs are gapped all over the place, when i pulled mine out they were at about .07 so it is a good idea to spend the whopping 16 bucks and do it while your in there